The Gulf Fritillary (Dione vanillae or Argraulis vanillae) is a striking, bright orange butterfly of the family Nymphalidae, subfamily Heliconiinae. It is a medium to large butterfly, with a wingspan of from 6 to 9.5 cm. Its underwings are buff, with large silvery spots. It takes its name from the fact that migrating flights of the butterflies are sometimes seen over the Gulf of Mexico. The Gulf Fritillary is commonly seen in parks and gardens, as well as in open country. Its range extends from Argentina through Central America, Mexico, and the West Indies to the southern United States, as far north as the San Francisco Bay Area on the west coast. It is occasionally found further north in the US.